This invention relates to a speed regulator for fuel injection pumps of internal combustion engines. The present invention is concerned, more particularly, with such a speed regulator which includes an intermediate lever pivotable about an axis defined by a shaft. Both the shaft and the intermediate lever are coupled with a flow quantity adjustment member of the injection pump and are acted on by a speed signalling device, with a speed dependent force, against the arbitrarily variable force of a main control spring and the force of starting spring.
An injection pump of the above-mentioned type is already known which includes a centrifugal force governor which acts against a main control spring of variable biasing, thereby adjusting the position of a regulating shaft. The displacement of the sleeve of the centrifugal force governor is thereby transmitted by a centrally located intermediate lever directly onto the regulating shaft and by a second lever which is rigidly connected to the intermediate lever onto a leaf spring which is held on an angled lever acted on by the main control spring and which is deformable on this angled lever as far as the position of an adjustable stop. The leaf spring thus cooperates with the main control spring against the positioning movement of the centrifugal force governor. As the positioning forces increase, the leaf spring is first deformed as far as its stop and thereafter the main control spring is deformed. Thus, the leaf spring which, during normal operation, constantly rests against its stop, enables a starting excess to be obtained which cuts off automatically after starting.
A fuel injection pump is also known which includes a centrifugal force governor which acts, with speed dependent force, on an intermediate lever coupled to the flow quantity adjustment member of the injection pump against the force of a main control spring and starting spring. In this case the main control spring is in the form of a tension spring and is secured to a drag lever which is pivotable about the same axis as the intermediate lever. The starting spring is also in the form of a tension spring and is secured to the outer end of the intermediate lever. Both springs have an adjustable lever as their second adjustment point and they can be adjusted in common via this adjustable lever. As the speed increases, the intermediate lever is moved by the centrifugal force governor against the force of the starting spring and then comes to rest against the drag lever which it lifts from a full load stop as the speed increases against the force of a main control spring, as a control measure.
The two above-mentioned types of speed regulators for injection pumps have the distinct disadvantage of not enabling the full load injection quantity to be adjusted according to the speed.